Poration



' .l. w. WHITE STOPLIGHT SWITCH l Julie 7, 1932f Original Filed April 17, 1926 A guentz JOHNIW-WH1TE ,Il F l Reissued June 7, 1932I UNITED STATES yP-irrala'l oFFlcE JOHN W. WHITE, OF DETROIT, MICHIGAN, ASSIGNR '.'IIO KELSEY-HAYES WHEEL COB.-

PORATION, F`DETR0IT,MICHIGAN,A 'CORPORATIONI'OFNEW YORK s'roPLrGH'r SWITCH original No. 1,744,940, dated January as, 1930, serial No. 102,'io1, mea Apriti 17, 1926, application for reissue mea June 29, 1931. serial No'. 547,75@

This invention relates to an improvement a, in a stop light intended to be mounted upon a motor vehicle equipped with a hydraulic or fluid pressure braking system.

The stop light itself is generally recognized as a very important accessory and whilecno particular diiliculty was experienced in installing it on a motor vehicle having mechanically applied brakes considerable dithculty has previously been 'experienced in installing it on motor vehicles having hydraulic l or fluid pressure braking systems. Q

The growth in the use of .hydraulic iluid pressure brake systems has created a demand for a simpler form of stop light actuating vmechanism and the primary object of this invention is to satisfy this demand by provid- .ing a stop light which is operatedlby any change in pressure in the lines Ot the hydraulic or Huid pressureo system, soas to indicate t0 an observer that some such change in the system is taking place.

Other objects of this invention will appear from a consideration of the following d escription taken in connection with the drawing which forms a part thereof, and in which Figure 1 is a perspective view illustrating the application of this invention to one form of a Huid pressure braking'system in which the brake is a plied by depressing a piston in a cylinder, t e braking piston and cylinder being shown in section;

Figure 2 is an enlarged sectional view of a portion of the braking cylinder illustrating the attachment of the stop light switch thereto;

Figure 3 is .an enlarged view of the stop lightswitch showing the parts in the idle position; p Figure 4 is a similar view of the switch showing the parts in the opertive position',

Figure 5 is ai side elevation of the disc which forms a part of the switch igure 6 is a bottom plan view of the disc; an p Figure 7 is a view partly in section illustrating the mannerfin which the terminals are mounted on the disc.

In the present. drawing is illustrated the application of this stop light cto 4a. hydraulic y cylinder by brake pedal, such as is shown in my cepending application Serialv No. 49,391, -liled` August 10, 1925. It will be clearly understood, however, that the switch shown atl tached to the cylinder can .be attached equally well to any other part of the system, and.

that it will respond to any increase inipressure which may be set up for some reason or other in the system. k,

In the drawing, the reference numeral 10 is employed to designate the floor board of a motor vehicle, in which is mounted at the proper angle a brake cylinder 11. In the cylinder 11 is mounted a piston '12, which is caused to move downwardly in the cylinder by the .application of pressure`to the foot piece 13 ofthe pistonplunger 14. From an examination of the zonstruction shown in they drawing and fromgthev description of .the

.mechanism which `will be found in "my copending application, it is of course clear that when the plunger 14 descends pressure is -created in the chamber 11 and transmitted through the coupling 15 to the brake lines 16 and 17.

` The switch or control for the stop light is designated generally by the numeral and may be mounted in an internally threaded hole 21 through the side wall of the cylinder 11. The switch 20 comprises a cuplike casing 22 terminatlng in an externally threaded sleeve 23 mounted in the hole 21.' The inside of the cup is connected to the interior of the the sleeve, the outer end of which is enlarged to form amouth 25.l Across .the mouth 25 is fixed a flexible diaphragm 26 suitably clamped in position by a ring 27 resting upon terminals of ,J

A suitable set screw meansf of a. passage 24 through. v

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of the disc 28 and is thus securely fixed in place. Over the end of the other terminal 3() is passed a spring clip 34 which will be clamped against the inner face of the disc when the terminal is fixed in place bypeen ing over the end of the terminal as shown in Figs. 3 and 4. The clip 34 has two outwardly projecting ends and resting loosely upon the diaphragm 26 is a mietal plate 36, which is held against the diaphragm at all times by the tips 35 of the clip 34. Conditions may arise which render it desirable that the switch 20 be installed on the other side of the cylinder 11i For that reason, a second hole 40 diametrically opposite the hole is drilled and tapped, being closed by the screw 41.

Gbviously, when parts are in the position shown in Figure 3, there is no connection between the terminals 30. When, however, the plunger 14 is depressed and pressure is created in the cylinder 1l, that pressure causes the diaphragm 26 to be distorted as shown in Fig. 4, raising the plate 36 until it contacts with both the terminals. lVhen this takes place the current `passes Afrom the battery to the stop ,light through the switch and illumines the latter in the usualmanner.

While one embodiment of this invention has been shown and described as applied to a braking system, applicant is not limited thereto, since it is obvious that other embodiments can be made applicable to this particular system or to other fluid operated systems without departing from the spirit and scope of this invention as set `forth in the following claims t Having thus set forth my invention, what I claim as new and for which I desire protection by Letters Patent is: y

1. A fluid operated switch comprising a cup like casinghaving a kpassage leading into the interior thereof, and adapted to contain fiuid, a diaphragm in said casing extending across and sealing said passage, a ring bear- `ing against the periphery of saiddiaphragm to secure it in place, a discv resting upon said ring and fixed in said ycasing by peening over the edge of said casing, akmetal plate in*y said ring resting freely against said diaphragm, a spring carried by said disc and holding said platein position against said diaphragm, and terminals projecting through said"` disc into said casing, into contact with the projecting ends of which said terminals said plate is brought shy the flexing of 'said diaphragm under the influence of fluid in said passage.

2. In a Huid operated switch, a cup like casing havinga passage leading into the interior thereof and' adapted to contain fluid, a disc fixed in the outer edgeof said casing, a diaphragm fixed in said casing across said passage, terminals projecting.` through said disc into said casing, a metal plate insaid casing resting freely l against said diaphragm and a spring carried by said disc holding said plate against said diaphragm and out of contact with said terminals, said plate being brought into contact with the projecting ends of said terminals by the flexing of said diaphragm under the influence of fluid in said passage. Y

3. A Huid operated switch comprising a cup likefcasingvhaving a passage leading into the interior thereof and adapted to contain fluid, an insulator head inserted in said cup,

spaced terminals mounted upon and extendy ing through said insulator head with inwardly projecting contact portions, a circuit closing member within said cup movable by Huid pressure in said passage into connection with said terminal contacts, and a flange on saidV cup peened over said insulator head to retain the parts in assembled relation and to wardly projecting contact portions and a resilient circuit closing diaphragm extending across within said cup and adapted to be actuated by the fluid pressure therein into connection with said terminal contacts, and a flange on said cup peened over said insulator head to retain the parts in assembledielation and to limit the flexing of said dia.- phragm. y

5. A Huid operated switch comprising a cup like casing having an external polygonal form and provided with a screw threaded nipple with a passage leading therethroughrinto the interiorof the cup and adapted( to contain fluid, an insulator head with inwa'rdly projecting cont-act VVportions and a resilient circuit/closing diaphragm extending across within said cup and adapted to be actuated by the Huid pressure therein intoconnection with said terminal contacts, and a flange on said cup peened over said insulator head to lretain the parts in assembled relation and to limit the fiexing of said diaphragm.

In testimony whereof I `afiix,my signature.

` ,JOHN WILLI/AM WHITE. 

